Dynamo-electric machines

Abstract

A rotating part for a high speed synchronous generator comprises a core of magnetic material, side walls of nonmagnetic material, and an outer circumferential portion. The outer circumferential portion is provided on its outside with an inner layer, an inner retaining ring, an outer layer and an outer retaining ring. The inner and outer layers are made up of magnetic and nonmagnetic portions. The retaining rings are of magnetic material. The greater strength and lighten weight of the nonmagnetic portions reduces the centrifugal forces on the magnetic portions. In an alternative embodiment, the outer circumferential portion comprises a number of layers comprising alternate portions of magnetic and nonmagnetic material, retained by rings of magnetic material. The nonmagnetic portions support the magnetic material, and prevent it from damage through centrifugal force. Another alternative embodiment includes recesses in the outer retaining ring and a nommagnetic material disposed in said recesses for securing the retaining ring. Another alternative embodiment comprises a magnetic core, a nomagnetic side wall of high strength, a magnetic portion, and a retaining ring divided into magnetic parts and nonmagnetic parts.

What is claimed is: 
     
       1. A rotating part for a dynamo-electric machine, comprising: a core portion of magnetic material;   an annular permanent magnet surrounding said core portion, said annular permanent magnet includes a plurality of annular permanent magnet rings separated axially by nonmagnetic rings;   an annular retaining ring of magnetic material for securing the annular permanent magnet; and   a side wall made of a nonmagnetic material adjacent said annular permanent magnet.   
     
     
       2. The rotating part according to claim 1, further comprising a plurality of layers of permanent magnet rings. 
     
     
       3. The rotating part according to claim 2, further comprising a retaining ring of magnetic material for each such layer. 
     
     
       4. The rotating part according to claim 2, wherein the nonmagnetic rings are equidistantly spaced along the axis of the rotating part. 
     
     
       5. The rotating part according to claim 1, wherein the retaining ring is made from a high strength magnetic alloy. 
     
     
       6. A rotating part for a dynamo-electric machine, comprising: an annular permanent magnet;   an annular retaining ring of magnetic material for securing the annular permanent magnet, the retaining ring having an outer circumferential recess therein; and   a nonmagnetic material disposed in the recess for securing the ring against centrifugal forces.   
     
     
       7. The rotating part according to claim 6, further comprising: a core portion made of magnetic material inside the annular permanent magnet; and   side wall portions made of a nonmagnetic material adjacent said annular permanent magnet.   
     
     
       8. The rotating part according to claim 6, wherein the annular permanent magnet includes a plurality of permanent magnet rings separated axially by nonmagnetic rings. 
     
     
       9. The rotating part according to claim 8, further comprising a plurality of layers of permanent magnet rings. 
     
     
       10. The rotating part according to claim 9, further comprising a retaining ring of magnetic material for each such layer. 
     
     
       11. The rotating part according to claim 9, wherein the nonmagnetic rings are equidistantly spaced along the axis of the rotating part. 
     
     
       12. The rotating part according to claim 6, wherein the retaining ring is made from a high strength magnetic alloy. 
     
     
       13. A rotating part for a dynamo-electric machine, comprising: a core portion of magnetic material;   a first annular permanent magnet having a plurality of outer circumferential recesses therein, said first annular permanent magnet surrounding said core portion;   a nonmagnetic material disposed in each of the recesses for securing the first annular permanent magnet against centrifugal forces; and   side wall portions made of a nonmagnetic material adjacent said first annular permanent magnet.   
     
     
       14. The rotating part according to claim 13, further comprising a second annular permanent magnet concentrically disposed about said first annular permanent magnet. 
     
     
       15. The rotating part according to claim 14, wherein said second annular permanent magnet includes an outer circumferential recess therein and a nonmagnetic material disposed in the recess of said second annular permanent magnet. 
     
     
       16. A rotating part for a dynamo-electric machine, comprising: an annular magnetic portion comprising a plurality of permanent magnet sections, the polarity of each of said permanent magnet sections being aligned in substantially the same direction; and   an annular retaining ring disposed about said annular magnetic portion, said retaining ring including two diametrically opposed magnetic portions and two diametrically opposed nonmagnetic portions.   
     
     
       17. The rotating part according to claim 16, wherein the outer periphery of a first half of the annular magnetic portion has a first polarity and the outer periphery of a second half of the annular magnetic portion has a second polarity. 
     
     
       18. The rotating part according to claim 17, wherein said nonmagnetic portions of the retaining ring are arranged at the junctions of the first and second halves of the annular magnetic portion.